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Biophysical and Biochemical Dynamics and Diffusion: Integrative Computational Modeling
03:00pm - 06:55pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 6
Rommie Amaro, Organizer, Presider; Dr Michael K Gilson, Organizer, Presider; Giulia Palermo, Organizer, Presider
Division: [PHYS] Division of Physical Chemistry
Session Type: Oral - Virtual
Division/Committee: [PHYS] Division of Physical Chemistry

This symposium will address the latest advances in application and development in molecular and Brownian dynamics, including simulations, new methods, and chemical physics.

Thursday
3655434 - All-atom molecular mechanics force fields benchmark on amyloid aggregation
03:00pm - 03:20pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 6
Division: [PHYS] Division of Physical Chemistry
Session Type: Oral - Virtual
Molecular dynamics (MD) simulations play a vital role in amyloid aggregation study that is crucial to the therapeutic agent development for Alzheimer’s Disease. The accuracy of MD simulation results strongly depends on the force field (FF) employed. In this work, we assess the applicability of 18 widely used atomistic molecular mechanics force fields (FFs) on amyloid aggregation using Aβ16–22 and VQIVYK (PHF6) peptides which are essential for the aggregation of Alzheimer’s Aβ peptides and tau-protein. Although, both Aβ16–22 and PHF6 peptides formed fibrils in vitro, the predominated forms of PHF6 fibrils are parallel β-sheets, while the Aβ16–22 fibrils are antiparallel β-sheets. We performed large-scale all-atom MD simulations in explicit water on dimer and oct-peptides systems for a total simulation time of 0.54 ms. We compared the FFs on the structural sampling of the amyloid peptides. Importantly, we benchmarked the FFs on the kinetics of the amyloid oligomer formation, which is rarely considered in previous FF comparisons. For the case of Aβ16–22, our result showed that (i) the AMBER94, AMBER99, and AMBER12SB do not predict any β-sheets; (ii) AMBER96, GROMOS45a3, GROMOS53a5, GROMOS53a6, GROMOS43a1, GROMOS43a2, and GROMOS54a7, form β-sheets too rapidly; (iii) AMBER99-ILDN, AMBER14SB, CHARMM22*, CHARMM36, and CHARMM36m achieved a balanced performance in reproducing the experimental findings on structures and kinetics. For the case of PHF6, the result pointed out that PHF6 β-sheet structures sampled by AMBER99SB-disp, AMBER14SB, GROMOS54a7, and OPLSAA are in favor of the antiparallel β-sheets, while the predominant type of β-sheet structures sampled by CHARMM36m is parallel β-sheet. Additionally, our simulation results also revealed that the protein-water interaction was overestimated in AMBER99SB-disp, in contrast the protein-protein interaction was overestimated in GROMOS54a7, and OPLSAA. In summary, AMBER99-ILDN, AMBER14SB, CHARMM22* and CHARMM36 are good candidates for studying Aβ assembly, while CHARMM36m is currently most suitable among the evaluated FFs for studying the aggregation of both Aβ and Tau through MD simulations.
Thursday
3655475 - Diffusion of Janus particle carrying cargo in a shear flow
03:20pm - 03:40pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 6
Division: [PHYS] Division of Physical Chemistry
Session Type: Oral - Virtual
Janus particle is nano to micro meter sized entity having two distinct faces, only one of which is chemically or physically active. A class of Janus particle is called active or self-propelled Janus which can move extracting energy from environment by creating concentration or thermal gradient at the vicinity of its active surface. Due to its self-propelled motion we model an active Janus particle carrying a cargo i.e. passive particle to form an active dimer. To use the dimer in different purposes, such as targeted drag (cargo) delivery in medical science, the detailed knowledge about its diffusive properties in presence of hydrodynamic interaction and flow field is necessary. Therefore we study the 3D dynamics of the active dimer suspended in a shear (Couette) flow. Using numerical simulations, we determine the diffusivity of such dimer in the presence of long-range hydrodynamic interactions for different values of its self-propulsion speed and the Couette flow. We observe that the effect of hydrodynamic interactions is greatly enhanced under the condition that self-propulsion is strong enough to contrast the shear flow. The magnitude of the effect grows with the size of the dimer’s constituents relative to their distance, which makes it appreciable under experimental conditions.
Active elastic dimer model suspended in a Couette flow

Active elastic dimer model suspended in a Couette flow


Thursday
3659212 - Simulating stochastic adsorption of diluted solute molecules at interfaces
03:40pm - 04:00pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 6
Dr. Jixin Chen, Presenter
Division: [PHYS] Division of Physical Chemistry
Session Type: Oral - Virtual
This work uses Monte Carlo simulations to connect stochastic single-molecule and ensemble surface adsorption of molecules from dilute solutions. Monte Carlo simulations often use a fundamental and time resolution to simulate each discrete step for each molecule. The adsorption rate obtained from such a simulation surprisingly contains an error comparing to the results obtained from the traditional method. Simulating adsorption kinetics is interesting in many processes such as mass transportation within cells, the kinetics of drug-receptor interactions, membrane filtration, and other general reaction kinetics in diluted solutions. Thus, it is important to understand the origin of the disagreement and find a way to correct the results. This report introduces a method to correct the results of adsorption rate from simulations. For example, one can bin finer time steps into time steps of interest to simulate the fractal diffusion, or simply introduce a correction factor for the simulations. Then two model systems, self-assembly monolayer (SAM) and biosensing on the patterned surface are simulated to check the accuracy of the equations. It is found that the adsorption rate of SAM is highly dependent on the conditions and the uncertainty is large. While the biosensing system is relatively accurate. This is because the concentration gradient near the interface varies significantly with reaction conditions for SAMs while relatively stable for the biosensing system.
Schemes of Monte Carlo simulations of diluted solute molecules near reflective (left) and adsorptive (right) surfaces.

Schemes of Monte Carlo simulations of diluted solute molecules near reflective (left) and adsorptive (right) surfaces.


Thursday
3637579 - NMR-based measurements of local electrostatic potentials around proteins: Examination of electrostatic theory
04:00pm - 04:20pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 6
Junji Iwahara, Presenter
Division: [PHYS] Division of Physical Chemistry
Session Type: Oral - Virtual
Electrostatic potentials computed from three-dimensional structures of biomolecules are widely used in molecular biophysics, structural biology, and medicinal chemistry. However, validation of the computed electrostatic potentials through experiments is rare and methodologically limited. Recently, we have developed a unique and powerful nuclear magnetic resonance (NMR) method that allows for straightforward and extensive comparison with electrostatic models for biomolecules and their complexes. This method utilizes paramagnetic relaxation enhancement (PRE) arising from analogous cationic and anionic cosolutes whose spatial distributions around biological macromolecules reflect electrostatic potentials. We demonstrate that this NMR method enables de novo determination of near-surface electrostatic potentials for individual protein residues without using any structural information. We applied the method to ubiquitin and the Antp homeodomain-DNA complex. The experimental data agreed well with predictions from the Poisson-Boltzmann theory. Thus, our experimental results clearly support the validity of the theory for these systems. However, our NMR data also illuminate certain weaknesses of the Poisson-Boltzmann theory. Together with our diffusion-based methods for investigating ions around biomolecules, this NMR method can deepen our understanding of biomolecular electrostatics.
<i>De novo</i> determination of effective near-surface electrostatic potentials from NMR PRE arising from charged PROXYL derivatives. Adopted from Yu, B., Pletka, C.C., Pettitt, B.M., Iwahara, J. (2021) <i>PNAS</i> 118, e2104020118.

De novo determination of effective near-surface electrostatic potentials from NMR PRE arising from charged PROXYL derivatives. Adopted from Yu, B., Pletka, C.C., Pettitt, B.M., Iwahara, J. (2021) PNAS 118, e2104020118.

Comparison of experimental and theoretical effective near-surface electrostatic potentials. Adopted from Yu, B., Pletka, C.C., Pettitt, B.M., Iwahara, J. (2021) <i>PNAS</i> 118, e2104020118.

Comparison of experimental and theoretical effective near-surface electrostatic potentials. Adopted from Yu, B., Pletka, C.C., Pettitt, B.M., Iwahara, J. (2021) PNAS 118, e2104020118.


Thursday
3660681 - Withdrawn
04:20pm - 04:40pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 6
Division: [PHYS] Division of Physical Chemistry
Session Type: Oral - Virtual

Thursday
3660701 - Localized approach to ill-posed inversion problem to study structure evolution of proteins using pulsed dipolar spectroscopy
04:40pm - 05:00pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 6
Madhur Srivastava, Presenter
Division: [PHYS] Division of Physical Chemistry
Session Type: Oral - Virtual
Revealing protein structural evolution is essential for determining its function and interaction with the environment, for understanding disease mechanisms. However, it is challenging for biophysical methods to observe structure evolution, especially at longer distances, limiting their application to few biological systems. Pulsed Dipolar Electron Spin Resonance Spectroscopy (PDS) is powerful method for obtaining such information between the distance ranges of 1 to 10 nm. In PDS, a dipolar signal is acquired from the interaction between a pair of spin labels, from which the distance distribution between them, P(r) may be obtained. Pseudo two-dimensional PDS experiments, such as Tm-filtered DEER, allow one to differentiate distance populations in inter-exchanging biomolecular systems. The reconstruction, however, of 2D distributions of distance populations using existing methods (such as Tikhonov regularization or Gaussian modeling) is challenging since relating the results of successive traces requires a priori information, which may not be readily available. To overcome this problem, we introduce the 2D Srivastava-Freed Singular Value Decomposition (2D SF-SVD) method that enables reconstruction of 2D distance distributions in a straightforward fashion, thereby permitting the accurate determination of measurable population changes for each distance. That is, the distance surface one obtains contains both the distance components transformed from the dimension of the dipolar signal and the dimension of traces, revealing changes in each distance population, and hence the structure evolution. We demonstrate this approach for the analysis of Tm-filtered DEER traces of protein A labeled with either R1 or R1p nitroxide spin labels.
Thursday
Intermission
05:00pm - 05:15pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 6
Division: [PHYS] Division of Physical Chemistry
Session Type: Oral - Virtual

Thursday
3648753 - Computational studies of full-length chicken and human stimulator of the interferon gene (STING) proteins in membrane systems
05:15pm - 05:35pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 6
Division: [PHYS] Division of Physical Chemistry
Session Type: Oral - Virtual
The stimulator of interferon gene (STING) protein, a signaling molecule, has become a recent focal point in immunological research and future drug discovery for its potential to enhance the ability to kill and fight infection greatly. Recognition of aberrant DNA species or cyclic dinucleotides (CDNs) in the cytosol activates Cyclic GMP-AMP synthase (cGAS) to produce a second messenger ligand, cGAMP, which binds and activates STING. This cGAS-STING signaling pathway triggers multiple signaling cascades leading to the production of Type I interferons. Since structural and dynamics effects through the biomolecular signaling pathways are complicated and not easily identified through traditional experiments, molecular dynamics (MD) has been used to study the dynamics and conformational changes that occur in protein structures.

This study carried out MD simulations for full-length chicken and human STING (chSTING and hSTING) proteins in the membrane environment to study structural deviations from the crystal structures published in Protein Data Bank. We looked at ligand-bound (holo - activated state) closed-form and ligand-unbound (apo – inactive state) open form in the membrane systems. We explored the dynamical differences between apo and holo states and the differences between chicken and human ligand binding sites in STING. Furthermore, the previous study suggested that the uncrossing of the linker region in hSTING increases the availability of cysteine residues to form disulfide bonds between neighboring hSTING dimers for polymer stabilization. So, we investigated the accessibility of cysteine residue 148 (Cys148) located in the linker regions of hSTING to explore its possibility in participation in polymer crosslinking. We believe that the information gathered from our study will add to our overall understanding of the conformational effects induced by ligand binding in a membrane environment and provide further insight into the STING signaling pathway.

Thursday
3658729 - Replica exchange transition interface sampling to simulate the kinetics of molecular transport through membranes
05:35pm - 05:55pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 6
An Ghysels, Presenter
Division: [PHYS] Division of Physical Chemistry
Session Type: Oral - Virtual

Permeability is a key property of biological membranes. Several strategies have emerged to predict membrane permeability from molecular dynamics (MD) simulations. The counting method uses the number of membrane crossings in a long conventional unbiased molecular dynamics simulation, which might lack sufficient statistics when the membrane forms a large free energy well or barrier. Alternatively, the widespread inhomogeneous solubility-diffusion (ISD) model can be used, which assumes purely diffusive kinetics. A methodology based on the Smoluchowsky equation was derived to extract the dynamics of oxygen permeation from these trajectories using Bayesian analysis (BA). The results of the methodology are the free energy across the membrane, and the diffusion profiles normal and parallel to the membrane surface, from which the permeability and the characteristic entrance, transit, and escape times of permeants as well as characteristic lengths have been derived. The described BA methodology has the advantage that radial diffusion can be analyzed. However, for a hydrophobic molecule like water, both the counting method and the BA methodology are confronted with convergence issues. Therefore we now present new methodologies for cases with poor statistics on the permeation events, such as a water molecule permeating through an lipid raft. One methodology is based on accelerated MD simulation but is limited to purely diffusive permeation. The other method is based on a divide-and-conquer strategy that can assess the exact kinetics of the permeation event, i.e. without assuming diffusive kinetics in the membrane, by extending the path sampling methodology to permeability calculations.

Thursday
3649171 - Unravelling the mechanism of reverse protonation in mKeima: Multiple conformers & their ultrafast excited-state dynamics
05:55pm - 06:15pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 6
Division: [PHYS] Division of Physical Chemistry
Session Type: Oral - Virtual
Soon after Osamu Shimomura discovered green fluorescent protein (GFP) from jellyfish, Aequorea Victoria, different colored fluorescent proteins (FPs) were identified from non-bioluminescent Anthozoa homologs of GFP and produced through various mutations. Apart from excited state proton transfer (ESPT), several other photoinduced reactions play an important role in the origin of colors in FPs which include photooxidation, photoreduction, photoisomerization, making & breaking of the covalent bond which further results in various interesting phenomena like large-stoke shifts, phototoxicity, photoactivation, photoconversion, photo-switching, the production of long-lived intermediates, blinking, permanent bleaching.
The chromophore of red fluorescent proteins (RFPs) has an extended N-acylimine group comparative to GFP chromophore which principally increases the conjugation and thus fluoresces in higher wavelength regions. Two ground state forms of Wild-type GFP and mKeima (a variant of RFP) have been known: neutral form and anionic form. The neutral form after excitation, undergoes an ESPT on a timescale of a few picoseconds, yielding the anionic form in the excited state which then fluoresces, and finally returns to neutral form via proton back-transfer in the ground state, termed as ground state proton transfer (GSPT). In this work, we have investigated the driving force behind the unusual phenomena of “reverse protonation” in mKeima in the different local environments by changing the pH. In addition, conformational heterogeneity of the chromophore showing reverse protonation effect in mKeima is reported in different pH environments. The role of the local environment of protein on the ultrafast excited-state dynamics coupled with the conformational changes in multiple species of chromophore following reverse protonation is explored. We further investigated the origin of dual-fluorescence in mKeima at low pH conditions and utilized this unique property in dual-color bioimaging.
mKeima samples in different pH environment along with their studies performed (in the right & left panel) and the schematic for transient absorption studies (in the middle panel).

mKeima samples in different pH environment along with their studies performed (in the right & left panel) and the schematic for transient absorption studies (in the middle panel).


Thursday
The azidonucleosides are well-known for their antiviral activities and recent studies have shown significant promise on using azidonucleosides as radiosensitizers for increasing the efficacy of tumor radiochemotherapy. Combining synthesis, electron spin resonance (ESR) spectroscopy, and theory, our work has shown that formation of the oxidizing nitrogen-centered radicals [RNH● (pi-type aminyl radicals) and R=N● (sigma-type iminyl radicals), eq. 1] from azidonucleosides (RN3) via their reactions with radiation-produced electrons (i.e., under reductive environment) provide the chemical basis of radiosensitization.
Our previous work has led to direct detection of RNH● formation at 77 K via irradiation of azidonucleosides also at 77 K. Azide anion radical (RN3) and the nitrene anion radical (RN●) detections were not possible by ESR (homogeneous glassy solution) as these species are too short-lived to be detected even at 77 K. Even at highly basic conditions (pH ca. 12), the expected RN● underwent protonation from the surrounding water forming RNH●. To address these issues, we have studied 5-azidouridine 1, 6-azidouridine 2, and 4-azido analogue 3. We now report on 77 K detection of (a) RN3 (4) formation from 3, (b) RNH● (5) formation from 1, and (c) R=N● (6) generation from 2 after gamma-irradiation at 77 K. Our results demonstrate how presence of the azido group at different positions (in 1, meta to N1 and N3, whereas in 2 and 3, ortho/para to N1 and N3) of the pyrimidine base affects the nature of the nitrogen-centered radicals that are formed.

Thursday
3662246 - Generating potential energy landscapes of membrane proteins in crowded lipid environments
06:35pm - 06:55pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 6
Shikha Nangia, Presenter
Division: [PHYS] Division of Physical Chemistry
Session Type: Oral - Virtual
Integral membrane proteins are ubiquitous in biological cellular and subcellular membranes. Despite their significance to cellular processes, the isolation of membrane proteins from their hydrophobic lipid environment and further characterization remains a challenge. Several computational approaches, such as docking or self-assembly simulations, have been used to obtain insights into membrane proteins; however, the promise of these approaches has been limited due to the computational cost. Here we present a new method called Protein AssociatioN Energy Landscape (PANEL) that provides an extensive and converged data set for all possible conformations of membrane protein associations using a combination of stochastic sampling and equilibrium simulations. The PANEL method generates a potential energy landscape describing the thermodynamic favorability of protein-protein association states and a frequency landscape representing their kinetic ease of formation. Based on this comprehensive dataset, we constructed a systematic approach to rank the dimer orientation taking both the relative stability of the protein dimers and their formation frequency into consideration. The PANEL method is efficient in identifying significant protein-protein interactions for a diverse set of protein families. The PANEL method is applicable to all membrane proteins and is freely distributed for use by the research community.
Advances in General Environmental Chemistry:
03:00pm - 07:00pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 9
Slawo Lomnicki, Organizer; Hanoz Santoke, Presider
Division: [ENVR] Division of Environmental Chemistry
Session Type: Oral - Virtual
Division/Committee: [ENVR] Division of Environmental Chemistry

This symposium is open to all papers or posters on environmental chemistry or engineering that may be beyond the focus of the specific topics addressed in other ENVR symposia.

Thursday
Introductory Remarks
03:00pm - 03:05pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 9
Division: [ENVR] Division of Environmental Chemistry
Session Type: Oral - Virtual

Thursday
3661807 - Biocomposite beads containing nickel nanoparticles for Cd (II) and Pd (II) removal from wastewater
03:05pm - 03:25pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 9
Division: [ENVR] Division of Environmental Chemistry
Session Type: Oral - Virtual
Abstract
In this study, a biocomposite containing nickel nanoparticles (OP-Ni) synthesized from orange peel (OP) waste was used to synthesize alginate nickel orange-peel beads (Alg/OP-Ni). The biocomposite was characterized using Fourier Transform Infrared Spectroscopy, X-ray diffraction, Field Emission Scanning Electron Microscopy, and Energy Dispersive X-ray spectroscopy. The co-adsorption characteristics of Cd (II) and Pd (II) ions from synthetic aqueous solutions using the newly prepared biocomposite were investigated with respect to pH, biomass dosage, contact time, initial concentration of ions, temperature, and stirring rate. Co-adsorption equilibrium data were modeled using Langmuir, Freundlich, and Dubinin-Ransehkevich (D-R) isotherms. The experimental data fitted well on the Langmuir isotherm suggesting the monolayer adsorption of the cadmium and lead ions onto Alg/OP-Ni. The monolayer adsorption capacity of Alg/OP-Ni for Cd (II) and Pd (II) ions obtained were 138 and 276 mg/g in monocomponent solutions and 224 and 317 mg/g in binary solution, respectively. D-R isotherm model data suggest that the co-adsorption process could include an important physisorption stage. Kinetic studies showed that the adsorption followed a pseudo-second-order kinetic model. Thermodynamic parameters indicated that Cd (II) and Pd (II) ions co-adsorption process was feasible, endothermic, and spontaneous in nature under-examined conditions.
Compared with other adsorbents, Alg/OP-Ni exhibited a greater adsorption capacity in both mono- and bi-component solutions, confirming that the biocomposite beads containing nickel nanoparticles can be suitable for the removal of heavy metals from wastewaters such as mining wastewaters.

Thursday
3646632 - Improving Rieske dioxygenase activity through enzyme engineering
03:25pm - 03:45pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 9
Division: [ENVR] Division of Environmental Chemistry
Session Type: Oral - Virtual
Today, fossil fuels are so commonly employed by the chemical industry as feed stocks for reactions, and as sources of the heat and pressure that drive them, that the chemical industry’s use of petroleum currently accounts for 14% of all greenhouse gas emissions, and the chemical industry is set to become the single largest driver of global oil consumption by 2030. In the Ball State Laboratory for Biocatalysis Research, we strive to develop new green-chemical tools that can contribute to alleviating the chemical industry’s reliance on fossil fuels.
With the recent advances in Synthetic Biology and Directed Evolution, the potential for engineering enzymes as robust, selective, and environmentally benign chemical catalysts has exploded. In the Ball State Laboratory for Biocatalysis Research, we have developed a novel periodate-based reactive assay system that has allowed us to pursue the engineering of Rieske dioxygenases. Rieske dioxygenases, with their unique ability to perform oxidative dearomatization to produce chiral cis-diol metabolites, have long been utilized as green-chemical catalysts in bioremediation efforts and by synthetic chemists, although their utility has been limited by their substrate scope and selectivity. By applying our novel assay system, we are developing new catalysts based on Rieske dioxygenases, which will expand the chemical utility of this class of enzymes. To this end, we have developed new dioxygenase catalysts with significantly increased activity in the production of valuable chiral synthons through rational mutagenesis and high-throughput screening.

Thursday
3649133 - Withdrawn
03:45pm - 04:05pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 9
Division: [ENVR] Division of Environmental Chemistry
Session Type: Oral - Virtual

Thursday
3656025 - Study on VOCs pollution control by Co-g-C3N4 activating PMS or H2O2 or AgAgBr/ZnO/TiO2 in EC-MFC, PEC-MFC systems
04:05pm - 04:25pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 9
Lifen Liu, Presenter
Division: [ENVR] Division of Environmental Chemistry
Session Type: Oral - Virtual
VOCs emission in gas phase or liquid phase need to be well controlled . We prepared monatomic catalyst Co-g-C3N4 and tested its photocatalytic activation of H2O2 and PMS for oxidation of Rhodamine B and liquid phase VOCs; Co atomically dispersed in g-C3N4, increased the visible light response and activity, and reduces the band gap. Co-g-C3N4/H2O2 and Co-g-C3N4/PMS systems were both effective in RhB degradation. The optimum Co loading capacity was 0.35 wt%. The stability tests of Co-g-C3N4/H2O2 and Co-g-C3N4/PMS photo-Fenton-like systems, indicated that Co-g-C3N4/PMS system performs better. In the Co-g-C3N4/PMS (0.1 mM PMS) and Co-gC3N4/H2O2 (9.8 mM H2O2) system, nearly 100% pollutant was degraded in respectively only 2 min and 16 min. The kinetic rate constant of Co-g-C3N4/PMS is 1.57 min-1 , and the removal capacity is 6.10 g/hg . The best conditions of Co-g-C3N4/PMS system are acidic and/or neutral, and the best conditions of Co-g-C3N4/H2O2 system are neutral. The Co-g-C3N4/PMS system has optimal performance, with PMS 0.10 mM, and catalyst 0.4 g/L . The Co-g-C3N4/PMS generated hydroxyl radical and sulfate radical as the main reactive oxidative species, while the hydroxyl radicals are the main species in Co-g-C3N4/H2O2 system. The use of metal monatomic catalyst to activate oxidants for catalytic oxidation degradation of VOCs provides a new idea for the catalytic oxidation of VOCs.
Another Ag/AgBr/TiO2-ZnO catalyst was also synthesized and tested in the microbial fuel cell as the photoelectrochemical cathodic catalyst for oxidation of VOC absorbed in liquid phase. It improved the performance of PEC-MFC system, to achieve oxidative removal of high concentration VOCs. A single cycle electrocatalysis with microbial fuel cell system (EC-MFC) and a single cycle photo electrochemical catalysis with microbial fuel cell system (PEC-MFC) were able to remove ethyl acetate and isopropanol successfully. The double-circulating photo electrochemical catalysis with microbial fuel cell system (PEC-MFC) could rapidly degrade the ethyl acetate in the absorbed solution. In summary, the composite catalytic materials and pollution control research provides new ways of thinking for practical application.

Thursday
Intermission
04:25pm - 04:40pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 9
Division: [ENVR] Division of Environmental Chemistry
Session Type: Oral - Virtual

Thursday
3657223 - Characterization of haloacetonitrile (HAN) precursors for the purpose of better understanding compounds that lead to HAN formation
04:40pm - 05:00pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 9
Division: [ENVR] Division of Environmental Chemistry
Session Type: Oral - Virtual
Haloacetonitriles (HAN) are unregulated nitrogenous disinfection byproducts (N-DBPs) in water distribution systems. These DBPs have been observed in systems that use chlorine, chloramine, or chlorine dioxide disinfection. HANs pose a higher risk as compared to eleven regulated DBPs based on their concentration and measures of their toxicity. Therefore, HANs have received increasing attention from researchers with an interest in identifying HAN precursors, and determining sources and control of these precursors. The goal of this research is to better characterize and possibly identify the molecules in raw and treated drinking waters that give rise to HANs following disinfection with chlorine.

For this research objective, we used automated preparative-scale fractionation to collect the retained and separated natural organic matter (NOM) in various water samples. These separations are based on some key chemical characteristics (e.g., effective molecular size, hydrophobicity or charge density). Fractions were analyzed for dissolved organic carbon, dissolved organic nitrogen, absorbance, and fluorescence, as well as HAN formation using mass spectrometry (quadrupole time of flight MS). The HAN formation tests showed the responsible groups are low molecular weight, hydrophilic organic structures and aromatic protein-like compounds. Fractions rich in aromatic content and colloidal and hydrophilic base fractions were further tested to determine the presence of amino acid residues. As part of this work, we established conditions for optimal uniform formation condition tests for dihaloacetonitriles and trihaloacetonitriles in water.

Thursday
3657523 - Withdrawn
05:00pm - 05:20pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 9
Division: [ENVR] Division of Environmental Chemistry
Session Type: Oral - Virtual

Thursday
3644225 - Barley responses to successive exposure of CeO2 nanoparticles (CeO2-NPs) and perfluorooctanesulfonic acid (PFOs) OnDemand
05:20pm - 05:40pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 9
Division: [ENVR] Division of Environmental Chemistry
Session Type: Oral - Virtual
Generational exposure of plants in a real environment is highly possible. This study investigated the effect of maternal exposure to CeO2-NPs on the performance of offspring plants exposed to PFOs in short-term and long-term exposures. To achieve this goal, barley seeds previously treated with 250 mg/kg of 0,10 and 40nm size CeO2 -NPs in the first generation were cultivated in 50mg/Kg PFOs in the second generation. The parameters that were measured in the short exposure study include biomass, chlorophyll content, lipid peroxidation, electrolyte leakage, and enzyme activity. In the full life cycle study, biomass yield, cerium uptake, elemental profile in root and shoot, cerium accumulation, and fatty acid profiles in grains were measured. Generally, CeO2- NPs and PFOs posed adverse effects in the metabolism of Barley, by lowering the overall plant performance and growth rate. Further research needs to be done on the effects of more nanoparticles on plants.
Thursday
3650204 - Utilizing DPPC liposomes to capture PCBs, an emerging class of environmental pollutants
05:40pm - 06:00pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 9
Division: [ENVR] Division of Environmental Chemistry
Session Type: Oral - Virtual
Persistent organic pollutants (POPs) are organic compounds that have the ability to accumulate in a wide variety of biological and ecological environments due to their resistive nature to chemical, thermal and photo degradation. Polychlorinated biphenyls (PCBs) are a class of man-made POPs that saw wide-spread use in commercial and industrial infrastructure as both an insulator and coolant in electrical transformers and capacitors. 2,2’,3,3’,4,4’-hexachlorobiphenyl (HCBP) was one of the most widely produced PCBs. As these mechanical structures fail or are discarded, PCBs are released into the soil, migrate to the water table, and eventually spread to nearby ecosystems by rain and wind. The stability of PCBs leave few options for environmental waste removal. Conventionally, liposomes have been used for their drug delivery capabilities, but here we have chosen to investigate their potential for the removal of this class of emerging environmental pollutants. Liposomes are small, nonpolar lipid bi-layered aggregates capable of capturing a wide variety of both polar and nonpolar compounds. Dipalmitoylphosphatidylcholine (DPPC) is a well characterized lipid that can be derived from natural sources. It is a phospholipid typically found as a major component of pulmonary surfactant mixtures. To assess the utility of liposomes prepared with pure DPPC in capturing PCBs, they were prepared using probe-tip sonication for both direct and passive incorporation of the HCBP compound. Assimilation of HCBP was assessed using differential scanning calorimetry and UV-Vis spectroscopy. For direct incorporation in the presence of HCBP, it was apparent that liposome stability generally decreased compared to pure DPPC liposomes based on a corresponding decrease in the phase transition temperature, Tm, from 40.8 °C to 37.4 °C. Additionally, an analysis of passive incorporation by UV-Vis spectroscopy showed an increase in the incorporation of HCBP proportionate to the length of exposure time up to 24 hours. Taken together these results demonstrate an exciting advance in the utility of liposomes as a tool for sustainable environmental cleanup.
Thursday
3638419 - Withdrawn
06:00pm - 06:20pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 9
Session Type: Oral - Virtual

Thursday
3661219 - Biodiesel from poultry waste and use of Icing leaf to remove the waste bad odour
06:20pm - 06:40pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 9
Olanike Salako, Presenter
Division: [ENVR] Division of Environmental Chemistry
Session Type: Oral - Virtual
The research project is to produce Biodiesel/Biogas from a poultry waste product. Waste from a Poultry-farm were collected and cultured anaerobically for four weeks of which automatically Biogas was produced (which is fuel: a mixture of Methane & Carbon(iv)oxide) but icing leaves were added to the culture to reduce the unpleasant smell and true to its ability to repel bad odor, on opening the decomposed organic matter from the poultry waste; the bad odor has been neutralized. So, we were able to stand to work with the specimen. However, to produce large scale biodiesel, purchase of equipment like digesters to breakdown the poultry waste without having to wait for four (4) weeks and running of underground pipes to carry the biogas produced as an alternate natural energy source must be done, for storage in the gas cylinder. The phytochemicals present in the icing leaf as plant growing on water (in the coastal area of Lagos, Nigeria) is also worthy of further analysis which is part of the significance of this research.
Thursday
3661925 - Withdrawn
06:40pm - 07:00pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 9
Division: [ENVR] Division of Environmental Chemistry
Session Type: Oral - Virtual

Electrochemistry-Enabled Catalysis for Energy, Chemicals and Materials:
03:00pm - 07:00pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 8
Yingwen Cheng, Organizer, Presider; Chong Liu, Organizer; Tianbiao Liu, Organizer; Dr. Pietro Papa Lopes, Organizer, Presider; Gang Wu, Organizer
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual
Division/Committee: [ENFL] Division of Energy and Fuels

Topics include, but are not limited to: Electrochemical water splitting, Electrochemical oxygen reduction, Electrocatalytic CO2and CO reduction to fuels, Electrochemistry-enabled N2reduction and NH3fuel cells, Electrochemistry-enabled biomass upgrade to chemicals and fuels, Electrochemistry-enabled organic and macromolecular reactions, Other electrochemistry-enabled activation/functionalization of small molecules

Thursday
3659452 - Single atom bifunctional electrocatalysts to realize high performance Li-Se batteries
03:00pm - 03:15pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 8
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual
The solubility of higher order polysulfides to the electrolyte, also known as the shuttle effect, and sluggish kinetics of electrochemical conversion reactions severely limit the improvement of electrochemical performance in Li-Se batteries. The advantages of carbon-based materials, such as high surface area and superior electronic conductivity, enables it to trap selenium within the host confinement, but the poor physical interaction between selenium and nonpolar carbon has little effect on polysulfide migration. Because of their excellent electrical conductivity and mechanical robustness, two-dimensional (2D) materials are good candidates for solving the challenges outlined above and enhancing electrochemical performance. Herein, we employ first principles-based density functional theory (DFT) simulations to investigate the mechanistic details of the anchoring behavior of single atom doped 2D materials such as MXenes and MoS2 substrates to lithium polyselenides (Li2Sen). The polysulfides anchoring on the basal planes are found to significantly improve with the incorporation of single atom catalysts (SAC) on the surface and the Li2Sen exhibits binding energies superior to that of the typical ether type electrolyte solvents. We investigate how the charge transfer between the anchoring materials (AMs) and Li2Sen species dictates the adsorption strength. We further study the Gibbs free energies of each elementary sulfur reduction reaction on the AMs, and the lower the free energies, the higher the catalytic activity of the AM surface, and hence the faster the discharge kinetics. Furthermore, our simulations provide information regarding Li2Sen decomposition on AMs, and the decreased energy barrier is expected to expedite the decomposition kinetics of lower order Li2Sen and improve the utilization of selenium in Li-Se batteries. Overall, our simulation results shed light on the adsorption behavior and chemical interactions of several AMs with Li2Sen, and develop understanding required for designing high-performance cathodes for Li-Se batteries.
Thursday
3659826 - Effect of polymer size and active site functionality on the electrocatalytic production of hydrogen in neutral water with [2Fe-2S] metallopolymer electrocatalysts
03:15pm - 03:30pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 8
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual
Efficient storage of intermittent renewable energy sources is required for the transition from fossil-fuel energy sources. An excellent candidate for the storage of renewable energy is hydrogen (H2) as it is a carbon-free high-density energy carrier. We have shown that polymer-supported [2Fe-2S] clusters containing protonated amine sidechains electrocatalyze the hydrogen evolution reaction (HER) in an aqueous TRIS buffer solution at pH 7.0 at a rate comparable to a standard platinum electrode. With the [2Fe-2S] cluster located in the interior of the polymer chain, the length of the polymer is shown to affect both the electrocatalytic current density and the overpotential of electrocatalysis, with smaller polymer lengths showing better performance. Preliminary results have been obtained on the performance of the [2Fe-2S] cluster active site when the position of the active site is shifted from the center of the polymer framework to the end.
Thursday
3660198 - Synthesis of Cr-doped Co3O4 electrocatalyst for electrochemical water oxidation in acid electrolyte
03:30pm - 03:45pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 8
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual
Electrochemical water splitting consists of two half-reactions, which are the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Kinetics of OER involves a four electron–proton coupled reaction which curtails the efficiency of water-splitting technology. To overcome this pitfall, developing an efficient and cost-effective electrocatalyst is a possible solution. Nevertheless, most of the efficient and earth-abundant OER catalysts in alkaline medium are not stable in acid electrolyte, due to the highly corrosive nature of acidic solutions. At present, noble metal-based catalysts such as iridium (Ir) and ruthenium (Ru) displayed promising ability in acid OER. However, to reduce the overall cost of water-splitting technology, we need to find cost-effective and efficient electrocatalysts for OER. In our work, we observed that doping of Cr-doping into the crystal lattice of Co3O4 largely enhances efficiency and stability in harsh acidic conditions. Among the doped samples, 10% doping of Cr showed promising OER activity with an overpotential of 366 mV at 10 mA cm-2 current density with a Tafel slope of 85 mV dec-1. The augmented OER activity is attributed to the high electrochemical surface area which is estimated from electrochemical double-layer capacitance (EDLC). These findings will help us in developing highly efficient and corrosive resistant earth-abundant catalysts for designing economically viable electrochemical water-splitting technology.
Thursday
3662517 - Particle size effect and active sites for ammonia electrosynthesis on Ru
03:45pm - 04:10pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 8
Dr. Xiaofeng Feng, Presenter
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual
Electrochemical reduction of N2 to NH3 has recently received considerable attention, because it may enable sustainable, distributed production of NH3 when powered by solar- or wind-generated electricity. However, typical catalysts show a low activity and selectivity for N2 reduction reaction (NRR) due to the barrier for N2 activation and the competing hydrogen evolution reaction (HER). A rational design of NRR catalysts relies on our understandings of structure-activity relationships and active sites for the NRR, and such study requires model catalysts with well-defined structures. Here we present a study of size-dependent activity for the NRR on Ru nanoparticle catalysts. We first tried colloidal synthesis method with polyvinylpyrrolidine (PVP) as a surfactant to control the size of Ru nanoparticles, while the derived Ru catalysts showed negligible activity for NRR, which was attributed to residual surfactant molecules that blocked catalyst surfaces. Therefore, we used atomic layer deposition (ALD) method to prepare Ru nanoparticles with controlled sizes ranging from 2 to 8 nm and clean surfaces. We further quantified the electrochemical active surface areas of Ru samples and derived surface-area-normalized activity for the NRR. Consequently, the effect of Ru nanoparticle size on the NRR activity and Faradaic efficiency was revealed, and Ru particles of around 4 nm in size showed the highest specific activity for the NRR. The particle size effect can provide insights into the active sites for the NRR and guidance on the design of NRR catalysts via surface site engineering.
Thursday

The electrochemical hydrogenation (ECH) of cis,cis-muconic acid, a biologically-produced intermediate that has recently been elevated to the status of platform chemical, was investigated. We show that in the absence of catalyst this route offers unprecedented selectivity to trans-3-hexenedioic acid (t3HDA), a novel monomer that is central to the synthesis of performance-advantaged polyamides. The reaction proceeds in solution through electronation-protonation under both acidic and alkaline conditions. As the electrode surface is not directly involved in the reaction, the process is unsensitive to biogenic impurities and raw, unpurified, fermentation broths can be processed directly, which opens interesting perspectives for process intensification and scale up. Moreover, tuning the broth’s composition creates synergies that enhance the productivity by up to 50-fold using industrially-relevant current densities (200-400 mA/cm2), without compromising on t3HDA selectivity. The addition of a precious metal catalyst enables the further electrohydrogenation of t3HDA to adipic acid using water as hydrogen source. This technology unlocks the cost-effective production of renewable Nylon 6,6 and of performance-advantaged Nylons based on the t3HDA platform.

Thursday
3639000 - Expanding the scope of electrocatalysis through catalyst design and operando spectroscopy
04:40pm - 05:05pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 8
Nikolay Kornienko, Presenter
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual
Electrochemical conversion of abundant feedstocks to fuels and value-added chemicals is rapidly gaining significance as a promising method to harness renewable electricity. To this end, research group develops heterogeneous catalysts (e.g. nanomaterials, MOFs) geared for the reduction of CO2 and oxidation of biomass platforms to fuels and value-added chemicals. Further, we establish strategies in emergent areas of electrocatalysis such as electrochemically forming and cleaving C-N bonds. Because the design of new catalytic systems is inherently linked to a precise understanding of how these reactions proceed on heterogeneous surfaces, we put considerable efforts in developing methodology for operando probing of these systems with vibrational spectroscopy. In all, I show how using these experiments provides key mechanistic information on surface reaction mechanisms that enhance our understanding of functional interfaces and how the research provides avenues for future materials design within the context of renewable energy electrocatalysis.

Thursday
Intermission
05:05pm - 05:15pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 8
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual

Thursday
3663280 - Atomic layer deposition to prepare low-Pt alloy catalysts for oxygen reduction
05:15pm - 05:40pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 8
Drew Higgins, Presenter
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual
This presentation will discuss the development of low-platinum oxygen reduction reaction (ORR) catalysts to address cost and performance challenges facing the deployment of polymer electrolyte fuel cells (PEFC) for hydrogen-based electrification of the transport sector. Particularly, an atomic layer deposition route involving the use of carbon monoxide as a nanoparticle growth inhibiter was developed for catalyst synthesis. The atomic layer deposition growth of Pt nanoparticles on both two-dimensional (planar) carbon substrates and high surface area carbon supports is demonstrated, with the ORR activity and stability of the atomic layer deposited catalysts surpassing those of commercial fuel cell catalysts. The translation of atomic layer deposition to prepare Pt-alloy catalysts with high activity and durability will also be presented on.
Thursday
3661539 - Iridium nanoconfined in the interlayer of restacked MnO2 nanosheets for an enhanced electrocatalytic oxygen evolution reaction
05:40pm - 05:55pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 8
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual
A promising strategy to generate hydrogen for a future hydrogen economy is via electrocatalytic water splitting, which uses an electrocatalyst and renewable electricity to convert water into hydrogen and oxygen. The anodic half-cycle involving the oxygen evolution reaction (OER), however, requires a high potential due to the four electron-proton transfer, making the overall reaction energy intensive in all pH ranges. Designing an active and stable OER catalyst to improve the reaction kinetics in both low and high pH will be beneficial for an economical production of hydrogen. Precious metals (e.g., Ir, Ru) and their oxides are excellent OER catalysts but their large-scale application is hindered due to their low earth-abundance. To address this issue, we have synthesized a series of OER catalysts with varying Ir wt.%, nano-confined through the restacking of MnO2 nanosheets (Ir/MnO2). The best OER activity was exhibited by 18 wt.% Ir/MnO2 with an OER overpotential of 298 mV and 220 mV at 10 mA cm-2 in 0.5 M H2SO4 and 1M KOH, respectively. These overpotentials are ~500 mV lower than the pristine MnO2 nanosheets and ~ 60-120 mV lower than commercial references with 20 wt.% Ir/C and IrO2 in both low and high pH, respectively. The physical characterization of the materials in this study was carried out with transmission electron microscopy (TEM), scanning electron microscopy energy dispersive X-ray spectroscopy (SEM-EDS), X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectrometry (XPS).
Thursday
3661865 - Low-temperature electrocatalytic approaches for liquid-phase light alkane upgrading
05:55pm - 06:10pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 8
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual
The growth of natural gas supplies, as well as ever-present environmental concerns, have led to efforts to develop catalytic technologies compatible with a more diverse portfolio of feedstocks for chemical production. The concept of distributed chemical manufacturing, which describes networks of production facilities operating at reduced scale and nearby to resources and end-use applications, is closely related – unconventional feedstock resources are often stranded, and production opportunities for renewable energy, proposed to drive the relevant chemical transformations, are not uniformly geographically distributed. In order to promote greater synthesis distribution, it is essential to explore the behavior of liquid-phase catalytic systems in mild conditions.
This presentation will describe efforts toward understanding the oxidative conversion of light alkanes in mild, aqueous conditions to oxygenates, including alcohols, aldehydes, and acids. Quantitative catalysis results will be presented for low temperature and pressure liquid-phase transformations of ethane and methane, with and without the application of electric potential. The accompanying Figure provides (left) quantification of products associated with the room-temperature and atmospheric-pressure partial oxidation of ethane in water with dispersed AuPd nanoparticle catalysts. These data are representative of one area that will be discussed – product distributions and conversions with increasing reaction times in batch conditions. The Figure also shows (right) representative results from our recent investigation into the anodic electrochemistry of the interaction of methane with platinum, which is a starting point for further studies into methane upgrading through electrochemistry.
<b>Figure 1.</b> (Left) Ethane partial oxidation by AuPd in mild conditions: oxygenate production rates quantified by NMR, GC, and titration experiments for representative batch reaction. (Right) Time-dependent operando SEIRAS results with potential held at 0.3 V vs RHE for 1 h in CH<sub>4</sub>-saturated 0.1 M HClO<sub>4</sub>. .

Figure 1. (Left) Ethane partial oxidation by AuPd in mild conditions: oxygenate production rates quantified by NMR, GC, and titration experiments for representative batch reaction. (Right) Time-dependent operando SEIRAS results with potential held at 0.3 V vs RHE for 1 h in CH4-saturated 0.1 M HClO4. .


Thursday
3659125 - Nanoflowers shaped Pd/Y2O3 anchored on functionalized CNTs through a metal–N system as bifunctional catalysts for both the EOR and ORR
06:10pm - 06:25pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 8
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual
Replacing both the commercial Pd/C and Pt/C catalysts with low-cost and efficient bifunctional systems would be significantly beneficial for the electrocatalytic ethanol oxidation reaction (EOR) and oxygen reduction reaction (ORR), and the utilization of these alternatives in fuel cells is highly important. Although numerous studies have reported various catalysts, the development of bifunctional catalysts with high catalytic activity and long-term stability is considerably challenging. In this study, we designed a new noble nanocomposite consisting of nanoflower (NF)-shaped Pd/Y2O3 grown on N-rich carbon nanotubes (N-CNTs) (denoted as Pd/Y2O3–NC) and used it as a bifunctional active catalyst for the simultaneous ORR and EOR. The N-rich carbon surface (NC) was prepared by acidification of CNT to avoid inherited stacking of its layers followed by the introduction of 1,8 naphthalene diamine (Nitrogen-rich compound) using a hydrothermal process. N-functionalization played a key role in the strong attachment of Pd/Y2O3 nanoparticles are anchored onto NC surface through Metal-N bonds, which improved the intrinsic catalytic activity of Pd/Y2O3–NC for both reactions in alkaline media. Pd/Y2O3–NC exhibited higher catalytic performance in terms of charge-transfer ability and current density and remained stable for a longer period of time than the benchmark Pd/C and Pt/C catalysts. This new Pd/Y2O3–NC nanocomposite could open up a promising approach as advanced catalysts towards both the ORR and EOR due to the unique NF-like shape of Pd/Y2O3 and the strong synergistic interaction between 1,8 naphthalene diamine and CNTs.
Thursday
3641758 - C-N triple bond cleavage via trans-membrane hydrogenation
06:25pm - 06:40pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 8
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual
The renewable energy-driven valorization of excess feedstocks into commodity chemicals and societally useful products constitutes a longstanding push in energy and sustainability research. To this end, this work pushes to expand the scope of green electrosynthesis by innovating a new approach to convert acetonitrile, industrially generated in excess and burned off, to in-demand ammonia and acetaldehyde products. Success here was enabled through the use of a Pd-membrane-based reactor which abstracted hydrogen atoms from water, which subsequently diffused through to a separate organic compartment in which they carried out the hydrogenation reaction. In this geometry, the reaction proceeded at 5.2 mA/cm2 partial current density and 60% Faradaic efficiency towards ammonia generation. Further, the transmembrane hydrogenation approach gave rise to an onset potential of 0.2V Ag/AgCl, surpassing previous state-of-the-art systems by 0.7V. A customized infrared spectroelectrochemcal setup was built up to probe the mechanism of the reaction, which was shown to proceed through an imine hydrolysis-like pathway, with the hydrogenation of the NHx species that remained to be the rate-limiting steps in the process. This work establishes a new route in electrochemical nitrile hydrogenation and general opens up promising avenues in green electrosynthesis.
Thursday
3651214 - CeO2 nanorods decorated with CoSe2 nanoparticles: An efficient electrocatalyst for the oxygen evolution reaction
06:40pm - 07:00pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 8
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual
Developing efficient and cost-effective catalysts for the oxygen evolution reaction (OER) is highly desirable for applications based on sustainable and clean energy technologies. Herein, we report the synthesis of nanocomposites consisting of CoSe2 nanoparticles (NPs) supported on CeO2 nanorods (CoSe2/CeO2) by two different methods (hydrothermal and electrodeposition) and investigation of their electrocatalytic performances in OER in 1.0 M KOH solution. The mass ratio of CoSe2 to CeO2 was varied to obtain the maximum catalytic activity. For the nanocomposites prepared by the hydrothermal route, it was observed that the one with the highest OER activity requires an overpotential of 282 mV to yield the current density of 10 mA cm−2 and exhibited a Tafel slope of 60 mV dec−1. For the electrodeposition method, an overpotential of 278 mV (at the current density of 10 mA cm−2) and a Tafel slope of 42 mV dec−1 were measured for the nanocomposite with the highest activity in OER. Moreover, the as-synthesized catalysts demonstrated excellent electrochemical stability in a 1.0 M KOH solution. The enhanced OER performance of the nanocomposites with the optimized mass ratio compared to the pristine CoSe2 can be attributed to the favorable synergistic interactions between CoSe2 and CeO2. Overall, due to its facile synthesis, excellent catalytic performance, and good electrochemical stability, CoSe2/CeO2 nanocomposite could be a promising OER electrocatalyst.
Advances in Energy and Fuels:
03:00pm - 05:20pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 3
Anne Co, Organizer, Presider; Wei Wang, Organizer, Presider
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual
Division/Committee: [ENFL] Division of Energy and Fuels
Thursday
Introductory Remarks
03:00pm - 03:05pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 3
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual

Thursday
For many decades, renewable feedstocks including lignocellulosic biomass are exploited to product biofuels. n-Alkanes, e.g., n-pentane, are used to enhance performance of diesel and gasoline engines. Low-temperature oxidation of n-pentane has been the topic of several theoretical and experimental studies.
In this context, a continuous flow fused-silica jet-stirred reactor (JSR) was used to study the low temperature (520-800 K) oxidation of 2500 ppm of n-pentane at a pressure of 10 atm, an equivalence ratio of 0.5 and a residence time of 1.5 s.
Complementary analytical techniques were used to identify oxidation products. Gas chromatography (GC-FID, TCD, MS) and Fourier-transform infrared spectrometry (FTIR) were used to identify light and stable chemical products including H2, O2, H2O, CO2, CO, C2H4, C3H6, etc. Also, liquid chromatography method, including high pressure and ultra-high-pressure liquid chromatography (HPLC, UHPLC), coupled with high resolution mass spectrometry (HRMS-Orbitrap Q-Exactive) was used to characterize specific low-temperature oxidation products such as: alkyl-hydroperoxides (C3H8O2, C4H10O2, C5H12O2), alkenyl-hydroperoxides (C2H4O2, C3H6O2, C4H8O2, C5H10O2), keto-hydroperoxides (C3H6O3, C4H8O3, C5H10O3) and highly oxygenated molecules (C5H10O4, C5H12O4, C5H10O5, C5H10O7) produced through multiply O2 addition on fuel’s radicals and internal H-shifts.
The experimental results were compared with kinetic model. All these results allowed us to better delineate species, and chemical reactions involved in n-pentane low temperature oxidation.

Thursday
3663226 - Photo induced force microscopy based nanometer resolution IR spectroscopy and application in energy research
03:25pm - 03:45pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 3
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual

Correlating spatial chemical information with the morphology of closely packed nanostructures remains a challenge for the scientific community. For example, supramolecular self-assembly, which provides a powerful and low-cost way to create nanoscale patterns and engineered nanostructures, is not easily interrogated in real space via existing nondestructive techniques based on optics or electrons. A novel scanning probe technique called infrared photoinduced force microscopy (IR PiFM) directly measures the photoinduced polarizability of the sample in the near field by detecting the time-integrated force between the tip and the sample. By imaging at multiple IR wavelengths corresponding to absorption peaks of different chemical species, PiFM has demonstrated the ability to spatially map nm-scale patterns of the individual chemical components of two different types of self-assembled block copolymer films. With chemical-specific nanometer-scale imaging, PiFM provides a powerful new analytical method for deepening our understanding of nanomaterials.
We will discuss three topics that demonstrate the application potential of PiFM application in energy research:
a. nanometer resolution chemical analysis of a solar cell material, the ternary cation halide Cs0.05FA0.81MA0.14PbI2.55Br0.45 (CsFAMA)-based perovskite visual sensor.
b. PiFM chemical imaging of a low cost high performance polymer solar cells with donor poly[(thiophene)-alt-(6,7-difluoro-2-(2-hexyldecyloxy) quinoxaline)] (PTQ10).
c. PiFM chemical imaging of lithium-ion migration during the charging process. We observed the high resolution mapping of delithiation process

Thursday
3643953 - Designing of new active layer molecules for solar cell applications: Empowering the next generation with solar energy
03:45pm - 04:05pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 3
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual
The increasing energy demand has expedited the research on developing low-cost and environment-friendly organic solar cells (EFOSCs). We efficiently designed and theoretically characterized new non-fullerene acceptor (NFA) molecules for organic solar cell (OSC) applications. These designed molecules have great potential to further improve the power conversion efficiency (PCE) of OSC devices. The designing of these molecules has been done by incorporating various end-capped units of the recently synthesized molecule to further improve the photovoltaic performances of the materials. The theoretical characterization of the designed materials has been carried out along with the reference (R) molecule to explore their structure−property relationship and photovoltaic and optoelectronic characteristics by various density functional theory (DFT) and time-dependent DFT (TD-DFT) approaches. Furthermore, narrower band gaps and highly red-shifted absorption behavior in contrast to R have been realized among all newly designed materials. Therefore, these NFA materials can be efficiently applied to fabricate OSC devices after blending with any suitable bandgap polymer (PTB7-Th) material. Our investigations have confirmed that the designed non-fullerene acceptors (NFAs) could be suitable candidates to achieve excellent device performances and offer significant directions to design effective NFAs for efficient OSCs.
Thursday
Intermission
04:05pm - 04:20pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 3
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual

Thursday
3665583 - Method to produce resin coated proppants at ambient temperature for hydraulic fracturing
04:20pm - 04:40pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 3
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual
In hydraulic fracturing operations, proppants coated with resin are used to enhance their crush strength, chemical resistance, and proppant flow back control. The majority of resin-coated proppants are prepared using phenol-formaldehyde resin (Novolac) hardened with hexamine at an elevated temperature of 380-425 oF in a plant setting. The objective of this study is to disclose a simple method to coat proppant at ambient temperature to provide free-flowing curable and pre-cured proppant without loss of any performance.
In this work, a free-flowing resin-coated proppant was prepared by coating 40/70 mesh sand substrate with liquid resin in a 1 Kg batch mixer. The coating was crosslinked with a hardener assisted by a catalyst and an accelerator for curing at ambient temperature. In some cases, diluents were mixed to lower the viscosity of resins, for easy and uniform coating onto the sand grains. Reinforcement of resin coating with carbon nanotube was also studied. Curable and the pre-cured proppants were prepared at room temperature. Coated sand was evaluated by sieve distribution, melt point, loss on ignition, fluid compatibility test, API proppant crush, and API long-term conductivity tests. Microscopy was used to ascertain the full dispersion of nanomaterial in the resin.
The liquid epoxy resin used for coating sand with a viscosity of 12,000 cp was diluted with 10-12.5% reactive diluents to lower its viscosity to 2500-3000 cp. Different kinds and combinations of Lewis acids and alcohols were employed for the quick curing and hardening of the resin. The free-flowing resin-coated sand was prepared from epoxy resin within 5 minutes by employing the catalyst accelerator. The melt point of the fully cured coated sand was greater than 450 oF which indirectly indicated that the prepared coating had a high glass transition temperature (Tg). API Crush resistance test on coated sand provided crush fines of less than 3% at 12k psi. In the unconfined crush resistance test cell, the coated sand did not form the consolidated pack under elevated closure stress and temperature indicating the proppant was fully pre-cured. Dilution of epoxy resin with reactive diluents helped in the uniform dispersibility of nanotubes in the resin as determined by microscopy. API long-term proppant pack conductivity showed improvement in the strength of the coated sand.

Thursday
3642006 - Fluorine-free synthesis of high purity Ti3C2Tx (T= -OH, -O) via alkali treatment
04:40pm - 05:00pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 3
Yan dong, Presenter
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual
MXenes—two-dimensional (2D) compounds generated from layered bulk materials, have attracted significant attention in
energy-related fields. However, most previous MXenes synthesis methods inevitably involve hydrofluoric acid, which is highly
corrosive and harmful to the performance of lithium-ion batteries and supercapacitors. Here, we report an alkali-assisted hydrothermal method to prepare a typical MXene—Ti3C2Tx (T= -OH, -O). This route is inspired from a Bayer process that is widely used in bauxite refining. The entire process is totally free of fluorine and yields multilayer Ti3C2Tx with ~92 wt.% in purity (via 27.5 M NaOH, 270°C).Without the -F terminations, the resulting Ti3C2Tx film electrode (~52 μm in thickness, ~1.63 g cm-3 in density) is 314 F g-1 via gravimetric capacitance at 2 mV s-1 in 1 M H2SO4. This surpasses (by ~214%) that of the multilayer Ti3C2Tx prepared via HF treatments. This fluorine-free method also provides an alkali-etching strategy for exploring new MXenes for which the interlayer amphoteric/acidic atoms from the pristine MAX phase must be removed

Thursday
3656327 - Electrical energy induced by no additional input power
05:00pm - 05:20pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 3
Mr. Osamu Ide, Presenter
Division: [ENFL] Division of Energy and Fuels
Session Type: Oral - Virtual
The author found a strange phenomenon of resonance transformer system. The resonance transformer applies electromagnetic resonance among a few electromagnetic cores.
While testing the resonance transformer, the DC input current to the system got down to zero except no effective current. Although the transformer was operating as the load terminal output some voltage. It means the resonance transformer outputs electrical power by no additional input power.

Microbial and Chemical Transformation of Environmental Contaminants and their Engineered Applications for Remediation:
03:00pm - 05:30pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 4
Enhyea Chung, Organizer; Byong-Hun Jeon, Organizer, Presider; Mayur Kurade, Organizer, Presider; Subbaiah Muthu Prabhu, Presider; Ian Bourg, Organizer, Presider
Division: [GEOC] Division of Geochemistry
Session Type: Oral - Virtual
Co-Sponsor/Theme: Theme: Nanoscience
Division/Committee: [GEOC] Division of Geochemistry

The contamination of ecosystem with numerous organic and/or inorganic pollutants is a global issue which is a massive burden on resources of industries and governments alike. The transport and transformation of these pollutants are highly influenced by natural processes that are either chemical or microbial. Understanding the complex interactions of these chemical and microbial processes assist in designing and optimizing the remediation tactics and therefore, improve science-based decision making for site management, priority-setting, and treatment selection. This session is aimed to gather the experts who are addressing recent advances in microbial and chemical processes affecting the fate, transport, and remediation of organic and inorganic subsurface pollutants. The session invites the experimental, modeling, and remedial contributions to understand microbial metabolism, chemical processes, and transport of pollutant in the natural systems, although we do not put a limit only to natural environment. The research contributions describing the role of mixed microbial communities in biotransformation and their mechanism of pollutant detoxification are invited. State-of-the-art applications to quantify and improve remediation performance or develop preventive measures are welcomed. We also encourage the submissions that address the emerging applications of nanotechnology for environmental pollution prevention, contaminant treatment, and hazardous waste site cleanup. The topics that would be covered in this session are, but are not limited to: •    Understanding the microbial and chemical interactions with the inorganic and organic contaminants in environment, and their influential role in remediation •    The in-situ and ex-situ remediation for decontamination of metals and organic contaminants at the contaminated sites including soil and water phases. •    Biogeochemical interactions of organic contaminants in natural environment. •    Interactions of geochemically important elements/contaminants (C, N, Fe, Mn, Hg, U, As and S) •    Application of these processes to develop remedial technologies for decontamination of inorganic and organic contaminants at the contaminated sites. •    Emerging molecular techniques for identification of microbial processes, interactions, and their networks in geogenic processes. •    Microbial communities, their role and mechanism of contaminant biotransformation in soil, water. •    Nanobased materials, such as nanoadsorbents, nanometals, nanomembranes, and photocatalysts for pollutant cleanup

Thursday
3655847 - Role of calcium carbonate minerals in natural attenuation of metals and radionuclides
03:00pm - 03:25pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 4
Nikolla Qafoku, Presenter
Division: [GEOC] Division of Geochemistry
Session Type: Oral - Virtual
Calcium carbonate (CaCO3) minerals occur naturally in many soils, subsoils and subsurface sediments. In addition, calcium carbonate coatings of reactive minerals are also common in many surface and subsurface terrestrial environments, altering reactivity and chemical behavior of minerals. Contaminants, such as metals and radionuclides, interact with CaCO3 minerals, and these molecular scale interactions may have important effects and controls over their mobility at larger scale, and for this reason are important to evaluation of the overall contaminant fate and transport under different dominant conditions in surface and subsurface environments. Significant advancements have been made recently toward identifying contaminant [e.g., uranium (U), iodine (I), chromium (Cr), arsenic (As)] attenuation mechanisms and interactions with carbonate minerals, which may also serve as a basis for developing in situ remediation strategies. This presentation will: i.) Present experimental and modeling data on molecular scale interactions of calcium carbonate minerals with contaminants; ii.) Discuss how these interactions affect or control contaminant fate and transport at larger scale; and iii.) Provide insights on the use of calcium carbonate natural attenuation pathways for the remediation of complex sites. Knowledge gaps will be also identified in this important research area.
Thursday
3661196 - Evaluating the biodegradation of diluted bitumen and heavy conventional crude oil in soil mesocosms
03:25pm - 03:45pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 4
Division: [GEOC] Division of Geochemistry
Session Type: Oral - Virtual
The oil extracted from western Canada is a heavily degraded, highly viscous form of petroleum known as bitumen. To be transported via pipeline, bitumen must be diluted with lighter hydrocarbon fractions to yield a less viscous blend of diluted bitumen, referred to as dilbit. Dilbit has chemical and physical properties that differ from conventional crude oils. To better understand how dilbit behaves in the environment in the event of a pipeline spill, we ran side by side dilbit and heavy conventional crude exposures, along with an untreated control, using soil-filled mesocosms. Soil cores were taken from the three mesocosm treatments at set intervals during a 104-day exposure. Phospholipid fatty acids (PLFAs), biomarkers for the active microbial population, were extracted from the soil. The stable carbon isotope (d13C) content of individual PLFAs and the radiocarbon content (Δ14C) of bulk PLFAs were then characterized. The Δ14C of bulk PLFAs ranged from -97.6‰ to -257.4‰ in dilbit affected samples and from -147.6‰ to -293.0‰ in conventional crude affected samples indicating that uptake of both dilbit and conventional crude hydrocarbons occurred. Control soils maintained modern Δ14C values (> -46‰). 16S ribosomal RNA genes were also extracted from the mesocosm soil cores. Amplicon sequencing revealed that the microbial communities changed over time and these changes were different between treatment types. The relative abundance of Polaromonas, a known hydrocarbon-degrading bacterial genus, was significantly increased following exposure to both dilbit and conventional crude oil. The strong evidence for microbial uptake of dilbit suggests that dilbit and conventional crude oil may be readily degraded by the native microbial community following a spill.
Thursday
3662463 - Effects of surface structural defects on Rb+ sorption on the quartz (101) surface
03:45pm - 04:05pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 4
Division: [GEOC] Division of Geochemistry
Session Type: Oral - Virtual
Mineral-water interfacial reactions control the fate and transport of nutrients and contaminants in natural environment. Natural mineral surfaces can contain various types of defects, imposing additional complexities on surface reactivities. In this study, we interrogated the types of molecular defects on the quartz (101)-water interface and their impacts on the sorption of Rb+ using in situ specular X-ray reflectivity. The structural defects of the idealized surfaces were expressed using the Robinson roughness model that describes the surface roughness using statistical variations in the coverage of stoichiometric surface planes with different heights. The structural defects of nonstoichiometric surfaces were modelled by considering partial occupancies of the constituent elements (i.e., Si and O) at the surface. The results reveal a strong correlation between these surface heterogeneities and Rb uptake, where the Rb coverages vary drastically (by a factor of ~three) on a single crystal surface. At a surface spot with a low heterogeneity (i.e., with little or no Si vacancies), Rb adsorbs mostly as an inner-sphere complex at ~2 Å from the surface. In contrast, at a surface spot with a higher heterogeneity (i.e., a higher defect density for the top Si and O atoms), additional Rb adsorbs both closer to the surface (i.e., at <1 Å) and farther from the surface (up to ~10 Å). This study provides a quantitative demonstration of the effects of surface heterogeneity on the geochemical behavior of minerals that strongly affects the fate of nutrients and contaminants in aqueous conditions.
Thursday
3658286 - Withdrawn
04:05pm - 04:25pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 4
Division: [GEOC] Division of Geochemistry
Session Type: Oral - Virtual

Thursday
3655209 - Predicting heavy metal adsorption on soil with machine learning and mapping global distribution of soil adsorption capacities
04:25pm - 04:45pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 4
Division: [GEOC] Division of Geochemistry
Session Type: Oral - Virtual
Studying heavy metal adsorption on soil is important for understanding the fate of heavy metals and properly assessing the related environmental risks. Existing experimental methods and traditional models for quantifying adsorption, however, are time-consuming to obtain and ineffective. In this study, we developed machine learning models for the soil adsorption of 6 heavy metals (Cd, Cr, Cu, Pb, Ni, and Zn) using 4420 data points (1105 soils) extracted from 150 journal articles. After a comprehensive comparison, our results showed that the gradient boosting decision tree had the best performance for a combined model based on all the data. The Shapley additive explanations method was used to identify the feature importance and their effects on the adsorption, based on which six independent models were developed for the six metals to achieve better model performance than the combined model. Using these independent models, the global distribution of heavy metal adsorption capacities on soils was predicted with known soil properties. Reversed models, including one combined model for all the six metals and six independent models, were also built using the same datasets to predict the heavy metal concentration in water when the adsorbed amount is known for a soil/sediment.
Thursday
3647811 - Functional group-specific inositol hexakisphosphate adsorption mechanism at the amorphous aluminum hydroxide-water interface
04:45pm - 05:05pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 4
Division: [GEOC] Division of Geochemistry
Session Type: Oral - Virtual
Inositol hexakisphosphate (IHP) is one of the most abundant organic phosphorus species in soils and sediments. Adsorption of IHP in soil minerals governs the bioavailability, solubility, and reactivity of IHP in natural environment. Due to its six phosphate functional groups (P groups), it is important to understand how different P groups react with soil minerals. This study investigated the functional group-specific IHP adsorption mechanism at the amorphous aluminum hydroxide (AAH)-water interface at pH 6.5, using the batch adsorption experiments, Zetasizer measurement, and solution 31P-NMR. The adsorption maxima of IHP in AAH was ~312.50 mmol kg-1. The presence of inner-sphere surface complexes was supported by the charge reversal effect observed in AAH zeta potential and the upfield shifts of various P groups in the NMR spectra. The solution NMR results further indicated that the functional group-specific adsorption of IHP was influenced by the initial IHP/AAH (mol kg-1) ratio. With a decreasing IHP/AAH from 2.5 to 1.25-1.67, the coordinated P groups changed from P2 only to P2, P1,3, and P4,6. The least reactive P group, P5, became reactive when further decreasing the ratio to <0.84. The increased aggregate size along with the observed multi-functional group coordination suggested the particle bridging effect. This study indicated that the surface sites availability of adsorbents could influence the functional group-specific IHP adsorption, thus affecting the solubility and bioavailability of IHP in the environment.

Thursday
3655349 - Soil phase desorption and degradation of sorbed carbazole, fluorine, dibenzothiophene and their binary and ternary mixtures by Pseudomonas aeruginosa RS1
05:05pm - 05:25pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 4
Division: [GEOC] Division of Geochemistry
Session Type: Oral - Virtual
In oil contaminated sites, PAH and heterocyclic PAH compounds have a tendency of getting adsorbed on soil and sediment particles due to their lipophilicity. Desorption of these compounds from the solid matrix leads to enhanced bioavailability, which could pose threats of toxicity, bioaccumulation and biomagnification. Bioremediation induced by indigenous microorganisms is a remediation measure for the contaminated sites.

In the present study, desorption and biodegradation experiments were conducted using soil sorbed carbazole (CBZ), fluorene (FLU) and dibenzohiophene (DBT) both individually and in binary and ternary mixtures, under both abiotic and biotic conditions. Biotic studies were performed using an efficient PAH degrading bacterial strain, Pseudomonas aeruginosa RS1. Bioavailability of the compounds in the system was determined by sequestering them from the aqueous phase on the Tenax beads under both abiotic and biotic conditions and eventually extracting them by liquid-liquid extraction followed by HPLC analysis. Residual concentration of the substrates in the soil were determined at various time points over a period of 32 days by Soxhlet extraction of the soil phase followed by HPLC analysis of the extracts. The combined desorption-degradation profiles of the compounds from the soil matrix were modelled using one-compartment model. Experiments conducted in binary and ternary mixtures of the compounds revealed substrate interactions and their impact on substrate degradation. Fig. 1 represents combined desorption-degradation profiles of CBZ when it was applied as the sole substrate at 90 mg/kg of soil.

One compartment model was a good fit to abiotic profiles in soil phase, but the model proved to be a poor fit for the biotic profiles. Decay profile in biotic systems more complex than 1st order decay. 1st order decay constant in biotic system (kb) was consistently higher than the abiotic ka. Possible factors affecting biotic decay profiles were lag in microbial uptake, non-linear biokinetics, heterogeneous distribution of sorbed compounds and preferential uptake of one compound over the other. Overall, direct bacterial interfacial uptake evident from soil phase concentration profiles was evident from the desorption and degradation profiles of the compounds.

Thursday
Concluding Remarks
05:25pm - 05:30pm USA / Canada - Pacific - March 24, 2022 | Location: Virtual 4
Division: [GEOC] Division of Geochemistry
Session Type: Oral - Virtual